Lenco trans

hummin cummins said:
It trashed the converter and welded either the forward clutches or the OD clutches together every time. The best it ran has been 10.02 fuel only and it weights 6200lbs

3rdgearofdriveclutch.jpg


3rdgeardrum.jpg
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Looks like it got plenty hot!


In the picture, looks like the direct clutch pack, takes a ton of abuse on the 2-3 shift. I can only imagine how much torque was being pushed through it on a 6200 lb truck.
 
The cultchflite doesn't address the welded clutch packs.
That's not to say it can't be built to hold as quite a few have done it.
 
Keating ran one in the truck at 3600 pounds. He has the clutch thing figured out.

Don't do a burnout in reverse. They can and will. Once. LOL Other than that it held up really well.

He had been running Mark Williams yokes. After several failures, he switched to CTM and never had another failure.
 
GANDJDIESEL said:
Reverse will not hold any power, I broke mine once giving it some power in reverse.
I know of two full body trucks in Canada that are putting the bruno/lenco with the tc lockup. They should be going by the NHRDA race in phoenix. We will see how the hold up.
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I hope it works for them...... The one trucks weighs about 5700 lb
 
hummin cummins said:
It trashed the converter and welded either the forward clutches or the OD clutches together every time. The best it ran has been 10.02 fuel only and it weights 6200lbs

3rdgearofdriveclutch.jpg


3rdgeardrum.jpg
Click to expand...

What valvebody were you running? That clutchpack does take a beating, but thats not normal at all. I've seen Rich Buckleys after 100 mid to low 9 second passes and they are no where near that burned. I have that clutch pack out of my tranny sitting on the bench now with 134 low 11 second passes on them in a 7000+ lb truck and you can still read the writing on them. What kind of pressures were you running?
 
A Lenco will hold no issues with a clutch, the trick will be getting the slip right. Meacham's truck still weighed 5500+ so it was no lightweight, and he cut a few 1.4-1.5 60fts with it with the 4-disc Molinari clutch. Also saw him go up in smoke and spin all four at TS from too much clutch, too quick.

Larry Larson has run high 6s at 3500 pounds and 2000+ hp and 2000+ lb-ft, so if he can do it, we should be able to also.
 
9 LIVES said:
The tranny is the cheap part....Its the adapters & clutch or converter setup that's 10K +
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I work on race cars for a living. You don't want a clutch in something that revs so low and has so much torque. It will be really difficult to make it consistent and fast. Only one turbo car (Brad Personett) has been able to do it with ANY regularity (and they pretty much have it down) but it took them a really long time to get it right.

Liberty is a bad idea- tripple shaft tooth engaged shifting- wont make 2 passes without breaking with a heavy truck. They have trouble with powerful cars doing it and went back to the Lencos in most all but prostocks and comp cars which both are low torque (comparitively). Putting a converter in front of the liberty makes it some easier (converter acts like a "cushion" to ease the harshness of the shifting) but will be LOW RELIABILITY. Trust me.

Lenco is clutch engage shifting and has lots of options and very tough. Reverser is the only weak part, but usually shows problems because it is misused or a combination that is idling to high. With these setups the internal shaft is spinning and you have to let the vehicle roll a touch to sometimes get the reverser to engage and if the shaft is spinning too fast (excessive engine speed) it is a crash when you engage. It will do it for a while- just have to keep an eye on it. If the driver doesn't smash it into gear- it will last a long time. It just takes some getting used to.

There are also several styles of Lenco- you should know that before you go buying stuff. CS1 is the oldest/ strongest/ largest. most easily recognizable that the shifter hole/ air pod hole is in the center of the transmission. CS2 is offset with lightweight components (nitrous promods/ blower promods and the like)- CS3 is smaller and lighter (IHRA prostocks and the like). If I was going to put together a combo for a diesel truck- CS1 is the most bullet proof and cheapest. TONS of ratios available. Don't use more than 3 spds on a auto setup.

Bruno's can be had fairly reasonably. You can get a new one for about 5K. Converters are....well...you can get whatever. Chance is my favorite, but everyone has a personal preference. You will want something large (for lock up in high gear) and tight so that you can run with low rpm's but loose enough to spool easy.

If you ahve any questions- I'll help however I can
 
racingjunk.com is a good place to start your look for this kind of stuff. also insidetopalcohol.com also has lots of stuff

I've got a buddy with a lenco bruno cs2 1.85 low 3 spd they are asking 5500 for the trans/bruno/air pods (shifts the transmission) and I think that includes the shift controller (box that tells the transmission when to shift so you don't have to do so)
 
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Blacksdieselhp said:
What valvebody were you running? That clutchpack does take a beating, but thats not normal at all. I've seen Rich Buckleys after 100 mid to low 9 second passes and they are no where near that burned. I have that clutch pack out of my tranny sitting on the bench now with 134 low 11 second passes on them in a 7000+ lb truck and you can still read the writing on them. What kind of pressures were you running?
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I am running the valve body from suncoast. I was one pass, it happened every time. Everyone from Ron, Ernie, my brother who owns a transmission shop tries to figure it out. We never did, thats why its parked till we do.
 
I should say, we are putting this trans in a different truck. One we can drive around and try to figure it out. The installation will be finished in a week or so. I will keep everyone posted on our findings.
 
hummin cummins said:
I am running the valve body from suncoast. I was one pass, it happened every time. Everyone from Ron, Ernie, my brother who owns a transmission shop tries to figure it out. We never did, thats why its parked till we do.
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I put in a brand new valve body last week in my duraflite and tested pressures. Was set quite low (way too low for racing). Pulled the pan and adjusted the pressure up and made some changes to the PCS, and now perfect. Did you test pressures before using?
 
IdahoRob said:
I put in a brand new valve body last week in my duraflite and tested pressures. Was set quite low (way too low for racing). Pulled the pan and adjusted the pressure up and made some changes to the PCS, and now perfect. Did you test pressures before using?
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Yes we did, we sent it to them to run it on their trans dyno. I want to say that everyone involved has gone above and beyond my expectations trying to alleviate the problem. The problem it my eyes has been that this is in our drag truck and it has a filled block and we cant drive it around. There is something that the dyno can't simulate like rpm's at launch or throughout the run to see what kind of heat it built in the converter. We are putting in our other truck, were running planning on running the 11:90 class with it. Again I want say thanks to everyone at suncoast and titus for all their help with our truck
 
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Billy Stocklin said:
racingjunk.com is a good place to start your look for this kind of stuff. also insidetopalcohol.com also has lots of stuff

I've got a buddy with a lenco bruno cs2 1.85 low 3 spd they are asking 5500 for the trans/bruno/air pods (shifts the transmission) and I think that includes the shift controller (box that tells the transmission when to shift so you don't have to do so)
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Damn, wish I could afford that right now!
 
I have ran a 100+ passes and no clutch issues. Just broken shafts. Truck weighs 6200lbs and pulled multiple 1.5 and one 1.49 60ft. Would like to know what pressures and the pressure rise is at the port.
 
Bponci said:
I have ran a 100+ passes and no clutch issues. Just broken shafts. Truck weighs 6200lbs and pulled multiple 1.5 and one 1.49 60ft. Would like to know what pressures and the pressure rise is at the port.
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Saweet! Im glad im getting advice from this guy :Cheer:
 
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